Google has launched its latest attempt to dethrone Facebook with one of its most aggressive broadsides ever, calling the leading social network "sloppy, scary and insensitive".

Google+ will be a new kind of social network that makes it much easier to share your comments, photos and internet links with selected groups of friends, instead of having to decide whether to publish something to everyone you know, the company said.

As Facebook has soared past 700 million users worldwide, and been crowned the No 1 site for display adverts in the US, Google has worried about losing out in the next phase of the internet. Its previous attempts at introducing a rival social network have ended in failure.

In a blog post announcing the new product, Google's senior vice-president of engineering, Vic Gundotra, indicated that Google had designed its new social network to resolve the typical gripes of Facebook users.

"The problem is that today's online services turn friendship into fast food – wrapping everyone in 'friend' paper – and sharing really suffers," he said. "It's sloppy. We only want to connect with certain people at certain times, but online we hear from everyone all the time. It's scary. Every online conversation (with over 100 'friends') is a public performance, so we often share less because of stage fright. It's insensitive."

Features on the new Google+ social network include video chats with up to 10 friends, and something it calls +Sparks, which will suggest content from around the web which users might want to share with select groups of friends.